The coyote is one of the most adaptable creatures on the planet. It has no natural enemy besides the wolf. The coyote is one of the last mammals to live when the world comes to its end they speculate.
If your looking for a real challenge try calling them in the East. The ratio for a call in is about 1 to 15 calls/sets for pro in the East. There aren't a lot of coyote hunting videos produced in the East due to lack of response, population and they're more skittish than their western species.